A lithographic apparatus is a machine that applies a desired pattern onto a target portion of a substrate. Lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In that circumstance, a patterning device, which is alternatively referred to as a mask or a reticle, may be used to generate a circuit pattern corresponding to an individual layer of the IC, and this pattern can be imaged onto a target portion (e.g. comprising part of, one or several dies) on a substrate (e.g. a silicon wafer) that has a layer of radiation-sensitive material (resist). In general, a single substrate will contain a network of adjacent target portions that are successively exposed. Known lithographic apparatus include so-called steppers, in which each target portion is irradiated by exposing an entire pattern onto the target portion in one go, and so-called scanners, in which each target portion is irradiated by scanning the pattern through the beam in a given direction (the “scanning”-direction) while synchronously scanning the substrate parallel or anti-parallel to this direction.
Many technological processes that are, used in the lithographic processing of rigid substrates are not applicable to flexible substrates. For instance, flexible substrates are formed from materials which may become damaged or destroyed if processed using the high temperatures associated with the processing of rigid substrates.
Photolithographic processes, or more generally photolithography based process blocks for structure fabrication are one of the most expensive processes in electronic IC manufacturing. In general, the high expense originates from the subtractive nature of these photolithographic processes, i.e. the deposition or growth of a layer of material on a substrate followed by a subsequent etching via a photoresist mask of parts of that material. A more cost effective option for structure fabrication (e.g. electronic IC manufacturing) is the use of an additive process such as printing, where material is added to the substrate only in places where that material is needed.
Many different printing processes exist, but each of such printing processes has one or more associated limitations. For instance, offset printing has limited registration capability and also uses materials (i.e. inks) with high viscosity. However, it is difficult to comply with the high viscosity requirement. This is because it is difficult to produce inks which have a high viscosity together with a high charge carrier mobility, which is another requirement that should be met. Inkjet printing, on the other hand, can use inks that have the desired high charge carrier mobility. However, ink materials (e.g. organic materials) with such a high charge carrier mobility generally have low stability. The utilization of inks with nanoparticles enables the production of, for example, stable transistors with high charge carrier mobility. However, by using only a single print step it may be difficult or impossible to print features sizes with micrometer resolution due to the low concentration of nanoparticles in the inks. In order to produce, for example, continuous lines using such inks, it may be necessary to repeat the printing of the same layer several times in order to bring a sufficient amount of nanoparticles onto the substrate. Aerosol nozzle spraying is another additive technique, but this technique also has disadvantages associated with it. Pixel-type printing is not desirable using aerosol nozzle spraying, because the switching on and off of an aerosol nozzle introduces an unacceptably long transient regime. Aerosol nozzle spraying is therefore limited to the field of vector writing.
It is therefore an aspect of the present invention to provide a lithographic method and apparatus that obviates or mitigates one or more of the challenges discussed above.